Grinding and polishing machine

ABSTRACT

An improved grinding and polishing machine incorporating a simplified flexible coupling between the driving shaft and the abrasive stone mounting structure which permits rigid mounting of the drive shafts and adjustment of the stone mounting frame relative to the shafts for proper spacing of the grinding stones on the machine.

United States Patent Kenneth W. Vezner 6107 Fremont North, Minneapolis, Minn. 55402 Nov. 7, 1969 Jan. 4, 1972 Inventor Appl. No. Filed Patented GRINDING AND POLISHING MACHINE 8 Claims, 3 Drawing Figs.

US. Cl 51/177, 15/49 R Int. Cl 1324b 23/00 Field of Search 51/174,

References Cited UNITED STATES PATENTS Pond Myers Limbers Vinella Biasoni Vezner Wilkinson Primary Examiner-William R. Armstrong AttorneySchroeder, Siegfried & Ryan ABSTRACT: An improved grinding and polishing machine incorporating a simplified flexible coupling between the driving shaft and the abrasive stone mounting structure which permits rigid mounting of the drive shafts and adjustment of the stone mounting frame relative to the shafts for proper spacing of the grinding stones on the machine.

' fPATENTEU JMF 4 E72 3 5 31 6 3 5 INVENTOR. KENNETH W. VEZNER GRINDING AND POLISHING MACHINE My invention relates to grinding, polishing or surfacing machines and more particularly to an improved terrazzopolishing machine.

Surfacing machines of this general type are known and in use. They normally employ a frame for mounting a drive motor and a coupling shaft connected thereto in driving relationship with a polishing or grinding surface. In machines of this type, the vibrations introduced by uneven surfaces to be polished require a flexible drive coupling between the drive shaft and the polishing stones. This has resulted in complicated driving structures which are fixed or nonadjustable in the rotational axis and which are subject to wear and excessive maintenance. In machines of this type, the grinding surface is provided by a plurality of stones which rotate in intersecting paths to adequately cover the surface to be polished. Adjustment of the position of these stones through their driving connection for proper spacing normally requires dismantling of the machines and repositioning of the gearing therein. Such maintenance and wear factors dictate high original expense and maintenance as well as excessive down time from a standpoint of usage.

The improved polishing machine of the present invention utilizes an improved coupling between the driving shafts thereof and the polishing stones or wheel to provide an arrangement which permits rigid mounting of the driving shafts and joumaling of the same to eliminate bearing and gearing wear while providing an arrangement in which the vibrations and shocks encountered by the polishing stones on uneven surfaces are not imparted to the driving apparatus. In particular, the improved grinding and polishing machine utilizes an arrangement in which the driving shaft mounts a deformable disc which in turn is mounted in a stone mounting frame in such a manner that the disc and frame at one edge thereof are coupled in a positive nonslip-type connection to provide a positive driving arrangement between the driving shafts and the polishing stones while permitting translational movement of the stone mounting frame relative to the driving shaft to absorb shocks imparted thereto. In addition, the coupling permits relative adjustment between the stone mounting frame and the driving shaft for accurate positioning of the mounting stones carried by each shaft of a grinding and polishing machine so as to properly space the stones driven by each shaft in their orbital path to provide a nonconflicting relationship therebetween. This improved coupling relationship eliminates the problem of disassembly of the machine to position stones relative to one another in their driven relationship. Thus, the machine may be accurately adjusted with respect to the polishing stones on each of the plurality of driven shafts and the coupling permits translational movement to absorb shocks while still providing a positive driving relationship to maintain angular spacing therebetween. This improved relationship eliminates bearing and gear wear by permitting a solid joumaling of the driving shaft and gearing and isolating the same from vibrations imparted to the polishing stones.

Therefore, it is the principal object of this invention to provide an improved grinding and polishing machine.

Another object of this invention is to provide in an improved grinding and polishing machine a simplified adjustable shock absorbing coupling between the stone mounting frame of the driving shaft thereof.

Another object of this invention is to provide in a grinding and polishing machine an improved coupling utilizing a disc which is deformable in a tilting direction and rigid in a driving direction.

Another object of this invention is to provide an improved grinding and polishing machine employing a coupling which is adjustable in a rotary direction for accurately positioning the location of driven polishing stones on a plurality of driving shafts relative to one another for noninterference purposes.

A still further object of this invention is to provide an improved grinding and polishing machine which is rugged in construction, relatively maintenance free, and easy to adjust.

These and other objects of this invention will become apparent from a reading of the attached description together with the drawings, wherein:

FIG. I is a perspective view of the improved grinding and polishing machine;

FIG. 2 is a plan view of a portion of the grinding and polishing machine with parts broken away showing the stone mounting frame and the shaft coupling therefor; and

FIG. 3 is a sectional view of the stone mounting frame and coupling of FIG. 2 taken along the lines 3-3 therein.

My improved grinding and polishing machine is shown herein as a terrazzo-polishing machine, indicated generally at 10 in FIG. 1 with parts, such as transporting wheels, electrical connection and control, omitted for simplicity. The machine includes a frame, indicated generally at 20, to which a guide handle 24 is attached. The cover section 22 of the frame mounts an electric motor 30 in a position where its output shaft extends through the cover and connects to gearing within the frame, indicated in part at 40, which in turn drives a plurality of output shafts, one of which is shown at 50. The machine may utilize two or more such drive or output shafts, each of which is journaled within the casing and carries a pinion 42 to cooperate with the gearing from the motor with each of the output shafts connecting to a stone mounting frame, indicated generally at 60. In surfacing or polishing machines of this type, the polishing or abrasive surface is an abrasive stone, such as is indicated at 65, and a plurality of such stones are connected to each mounting frame for each drive shaft such that they may be rotated in a circular path from the drive shaft with the circular paths of the plurality of stones intersecting in the area beneath the frame for effective and adequate polishing or grinding of a surface. Such machines will normally be used on extremely roughened surfaces with the purpose to grind them to a smooth surface through abrasive wear caused by the polishing stones traversing the surface to be polished. The stone mounting frames for each shaft normally mount three equally distantly spaced stones for effective coverage of the surface to be contacted. Because such surfaces are uneven and quite hard, normally concrete with terrazzo-type rock positioned therein, excessive vibration and translational forces will be transmitted back through the stones as they are rotated. Thus, the stone mounting frame is connected to the drive shafts through a flexible coupling which will allow the stone mounting frame to tilt translationally as the stones are rotated to traverse and grind high spots in the surface being polished.

In FIGS. 2 and 3, the stone mounting frame and its flexible coupling to the drive shaft 50 is shown in plan and section to disclose the shape and relationship of parts. The stone mounting frame 60 is a cup-shaped structure generally cylindrical in outline, as indicated at 66, and has a plurality of stone mounting flanges 67 formed integral therewith and projecting therefrom, the stone mounting flanges being generally cylindrical in form and adapted to position the cylindrical grinding stones. The bottom of the cup-shaped portion of the mounting flange is open, as at 68, to provide an annular lip section 69 with the top extremity being open in its entirety. The inner wall surface of the cylindrical portion is tapered or shaped conically with inwardly sloping walls toward the bottom lip 69. This cylindrical portion of the mounting frame 60 mounts a cylindrical disc of deformable material, such as hard rubber, which has a cylindrical metallic hub 82 at the center of the same, the hub having collar portions 84 at the top and bottom extremity and an undulating surface 85 at the center of the same. The disc is constructed by molding the hard rubber or deformable material onto the hub to provide a positive and solid connection between the hub and the inner or central portion of the cylindrical disc. The outer peripheral wall is sloped in the shape of a truncated cone, as at 88, to fit into and mate with the sloped inner conical surface of the mounting flange. The thickness of the hub is slightly greater than the depth of the inner surface of the mounting flange such that the disc may be positively secured at its outer peripheral surface into the mounting flange by means of a clamping cover 90 which is annular in form and has securing apertures therein through which securing bolts 92 extend to flt into tapped apertures 94 in flange portions 95 formed integral with the outer surface of the mounting flange. Thus, with the clamping ring 90 in place and the bolts 92 secured into the threaded apertures 94 of the flanges 95, the peripheral edge of the disc will be clamped solidly to the mounting flange. The upper and lower surfaces of the disc between the clamped edge and the mounting hub 82 is free or exposed so as to be capable of displacement or deformation. The hub 82 has a suitable key slot 97 therein which mates with a key slot 98 in the extremity of the drive shaft 50 so that a suitable key member 99 may be inserted therein to positively lock the drive shaft to the hub. The drive shaft in turn is supported at this lower or driving extremity through a bearing, indicated generally at 100, whose inner race 102 is suitably attached to the shaft, such as by press fitting, and whose outer race 104 is adapted to be secured into the base or bottom 105 of the mounting frame for the machine through suitable means, such as lock bolts threaded into apertures 106 in the outer bearing race.

Thus, the shafts 50 will be rigidly secured in the mounting frame and joumaled therein through suitable bearing means, such as the bearing 100 shown at the bottom or lower portion of the mounting frame, to impart or provide for rotational movement of the same but being rigidly secured against translational movement. The shaft is in turn connected to the deformable disc 80 at its hub through a suitable key 99 positioned through key slots 97, 98 in the hub to rigidly secure the disc at the center thereof to the shaft. The outer peripheral surface of the deformable disc is rigidly clamped to the mounting frame, as indicated above, to provide positive rotational movement to the mounting frame and the stones therein from the shaft with operation of the motor 30. Any translational forces imparted to the mounting frame will be absorbed by deformation of the flexible coupling formed by the deformable disc 80 connected positively to the mounting frame and the shaft, as previously identified, and positioned so as to permit tilting movement of the frame relative to the shaft with engagement of rough surfaces with the grinding stones. Thus, the shocks imparted by such grinding will be dampened and masked from the shaft eliminating bearing wear and gear wear to the driving shaft. In addition, the relative position of the mounting frame may be rotationally adjusted relative to the shaft for positioning of the stone holding flanges and hence the stones therein relative to the stones on the other mounting frames of the machine. Since the circular path of the stones will intersect underneath the machine and at the center thereof for maximum and efl'ective polishing coverage, it is necessary that the stones be positioned relative to one another so as not to interfere or contact as the machine is operated. By simply releasing the clamping ring and adjusting the position of the mounting frame relative to the deformable disc, such adjustment is effected without altering shaft position, gearing or the like. Thus, the improved terrazzo-polishing machine provides an arrangement in which the machine may be adjusted with respect to stone positioning and may be readily disassembled at the mounting frame for maintenance and replacement of worn stones without requiring disassembly of the complete machine. The deformable disc will absorb shocks imparted to the stone mounting frame reducing wear and shocks on the shafts and bearings, as well as the gearing connected thereto.

lclaim:

1. A polishing machine comprising, a frame, a drive motor mounted thereon, a plurality of drive shafts positioned in the frame and coupled to the driving motor, a stone mounting frame connected to each of the drive shafts and including a plurality of spaced stone holders thereon, flexible coupling means connecting the stone mounting frames to each of the drive shafts including deformable and rigid parts which are relatively adjustable with respect to one another and which errnit translational movement of the stone holder relatiye to he shaft, said deformable part of the flexible coupling being a cylindrical disc of hard rubber adapted to be rigidly connected to a driving shaft and said stone mounting frame including a cup-shaped portion adapted to receive and mount the cylindrical disc of hard rubber, and joumaling means positioned in the mounting frame and rigidly mounting the shaft against translational movement relative to the frame, said disc of hard rubber including a metal hub at the geometric center thereof with a key slot therein adapted to be connected through a key slot in the drive shaft.

2. The polishing machine of claim 1 in which the cupshaped portion of the stone mounting frame has open, bottom and top portions and includes an annular clamping ring adapted to be connected to the cup-shaped portion of the mounting frame at the top to clamp the deformable disc of rubber therein.

3. The polishing machine of claim 2 in which the cylindrical disc of hard rubber has an inwardly tapered peripheral side surface and the cup-shaped portion of the mounting frame has an inwardly sloped annular surface adapted to receive and mate with the surface of the deformable part.

4. The polishing machine of claim 3 in which the metal hub mounting the deformable rubber disc has an undulating peripheral surface to which the rubber disc is molded.

5. The polishing machine of claim 4 in which the stone mounting frame includes a plurality of equally spaced stone holding flanges formed integral with the cylindrical portion of the frame and positioned outwardly from the geometric center thereof.

6. A polishing machine comprising, a frame, a drive motor mounted thereon, a plurality of drive shafts positioned in the frame and coupled to the driving motor, a stone mounting frame connected to each of the drive shafts and including a plurality of spaced stone holders thereon, flexible coupling means connecting the stone mounting frames to each of the drive shafts including defomiable and rigid parts which are relatively adjustable with respect to one another and which permit translational movement of the stone holder relative to the shaft, each of said stone mounting frames having a cylindrical portion with open, bottom and top sides and stone mounting flanges positioned on the peripheral surface thereof with the deformable member being a flexible disc rigidly secured to the shaft at the center thereof and adapted to fit into and be clamped within the cylindrical portion of the stone mounting frame with the rigid connection of the shaft to the disc being disposed at the open, top and bottom sides of the mounting frame.

7. The polishing machine of claim 6 in which a portion of the top side of the cylindrical portion of the mounting frame is removable to releasably clamp the deformable disc therein and permit repositioning of the mounting frame relative thereto.

8. The polishing machine of claim 7 in which the stone mounting flanges are three in number and the plurality of drive shafts coupled to the mounting frame are at least two positioned and equally spaced from one another on the mounting frame with the stone holding flanges of the stone mounting frame connected thereto being positioned in intersecting orbital paths. 

1. A polishing machine comprising, a frame, a drive motor mounted thereon, a plurality of drive shafts positioned in the frame and coupled to the driving motor, a stone mounting frame connected to each of the drive shafts and including a plurality of spaced stone holders thereon, flexible coupling means connecting the stone mounting frames to each of the drive shafts including deformable and rigid parts which are relatively adjustable with respect to one another and which permit translational movement of the stone holder relative to the shaft, said deformable part of the flexible coupling being a cylindrical disc of hard rubber adapted to be rigidly connected to a driving shaft and said stone mounting frame including a cup-shaped portion adapted to receive and mount the cylindrical disc of hard rubber, and journaling means positioned in the mounting frame and rigidly mounting the shaft against translational movement relative to the frame, said disc of hard rubber including a metal hub at the geometric center thereof with a key slot therein adapted to be connected through a key slot in the drive shaft.
 2. The polishing machine of claim 1 in which the cup-shaped portion of the stone mounting frame has open, bottom and top portions and includes an annular clamping ring adapted to be connected to the cup-shaped portion of the mounting frame at the top to clamp the deformable disc of rubber therein.
 3. The polishing machine of claim 2 in which the cylindrical disc of hard rubber has an inwardly tapered peripheral side surface and the cup-shaped portion of the mounting frame has an inwardly sloped annular surface adapted to receive and mate with the surface of the deformable part.
 4. The polishing machine of claim 3 in which the metal hub mounting the deformable rubber disc has an undulating peripheral surface to which the rubber disc is molded.
 5. The polishing machine of claim 4 in which the stone mounting frame includes a plurality of equally spaced stone holding flanges formed integral with the cylindrical portion of the frame and positioned outwardly from the geometric center thereof.
 6. A polishing machine comprising, a frame, a drive motor mounted thereon, a plurality of drive shafts positioned in the frame and coupled to the driving motor, a stone mounting frame connected to each of the drive shafts and including a plurality of spaced stone holders thereon, flexible coupling means connecting the stone mounting frames to each of the drive shafts including deformable and rigid parts which are relatively adjustable with respect to one another and which permit translational movement of the stone holder relative to the shaft, each of said stone mounting frames having a cylindrical portion with open, bottom and top sides and stone mounting flanges pOsitioned on the peripheral surface thereof with the deformable member being a flexible disc rigidly secured to the shaft at the center thereof and adapted to fit into and be clamped within the cylindrical portion of the stone mounting frame with the rigid connection of the shaft to the disc being disposed at the open, top and bottom sides of the mounting frame.
 7. The polishing machine of claim 6 in which a portion of the top side of the cylindrical portion of the mounting frame is removable to releasably clamp the deformable disc therein and permit repositioning of the mounting frame relative thereto.
 8. The polishing machine of claim 7 in which the stone mounting flanges are three in number and the plurality of drive shafts coupled to the mounting frame are at least two positioned and equally spaced from one another on the mounting frame with the stone holding flanges of the stone mounting frame connected thereto being positioned in intersecting orbital paths. 